3 files changed, 28 insertions, 0 deletions

diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index b13123424e49..f031d1c925f0 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -61,6 +61,7 @@ struct inode *ramfs_get_inode(struct super_block *sb, int mode, dev_t dev)
                 inode->i_mapping->a_ops = &ramfs_aops;
                 inode->i_mapping->backing_dev_info = &ramfs_backing_dev_info;
                 mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER);
+                mapping_set_unevictable(inode->i_mapping);
                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
                 switch (mode & S_IFMT) {
                 default:
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 5da31c12101c..09164d2c5c27 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -32,6 +32,28 @@ static inline void mapping_set_error(struct address_space *mapping, int error)
         }
 }
 
+#ifdef CONFIG_UNEVICTABLE_LRU
+#define AS_UNEVICTABLE  (__GFP_BITS_SHIFT + 2)  /* e.g., ramdisk, SHM_LOCK */
+
+static inline void mapping_set_unevictable(struct address_space *mapping)
+{
+        set_bit(AS_UNEVICTABLE, &mapping->flags);
+}
+
+static inline int mapping_unevictable(struct address_space *mapping)
+{
+        if (mapping && (mapping->flags & AS_UNEVICTABLE))
+                return 1;
+        return 0;
+}
+#else
+static inline void mapping_set_unevictable(struct address_space *mapping) { }
+static inline int mapping_unevictable(struct address_space *mapping)
+{
+        return 0;
+}
+#endif
+
 static inline gfp_t mapping_gfp_mask(struct address_space * mapping)
 {
         return (__force gfp_t)mapping->flags & __GFP_BITS_MASK;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 2804d23e2da7..9babfbc1ddc8 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2332,11 +2332,16 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
  * lists vs unevictable list.
  *
  * Reasons page might not be evictable:
+ * (1) page's mapping marked unevictable
+ *
  * TODO - later patches
  */
 int page_evictable(struct page *page, struct vm_area_struct *vma)
 {
 
+        if (mapping_unevictable(page_mapping(page)))
+                return 0;
+
         /* TODO:  test page [!]evictable conditions */
 
         return 1;